gpg keyrings in /usr/share/debug-me/ will be checked
to see if a connecting person is a known developer of software
installed on the system, and so implicitly trusted already.
Software packages/projects can install keyrings to that location.
(Thanks to Sean Whitton for the idea.)

make install installs /usr/share/debug-me/a_debug-me_developer.gpg,
which contains the key of Joey Hess. (stack and cabal installs don't
include this file because they typically don't install system-wide)